U.S. patent number 5,686,385 [Application Number 08/461,423] was granted by the patent office on 1997-11-11 for agricultural microcapsule and production thereof.
This patent grant is currently assigned to Takeda Chemical Industries, Ltd.. Invention is credited to Kanji Akashi, Kazutaka Kitagawa, Chikara Tanabayashi.
United States Patent |
5,686,385 |
Akashi , et al. |
November 11, 1997 |
Agricultural microcapsule and production thereof
Abstract
The present invention provides microcapsule comprising
agricultural active ingredients with improved physical properties,
and an agricultural composition comprising said microcapsule. An
agricultural microcapsule having a diameter of not more than 50
.mu.m comprises an agricultural active ingredient in a
water-soluble coating material. As an agricultural composition
comprising said microcapsules, DL dust, solidified emulsifiable
concentrate can be provided. According to the present invention,
the agricultural active ingredient is stabilized, agricultural dust
can be mixed with even incompatible, liquid agricultural active
ingredient, and agricultural microcapsule has excellent handling
properties.
Inventors: |
Akashi; Kanji (Tsukuba,
JP), Tanabayashi; Chikara (Tsukuba, JP),
Kitagawa; Kazutaka (Tsukuba, JP) |
Assignee: |
Takeda Chemical Industries,
Ltd. (Osaka, JP)
|
Family
ID: |
18384942 |
Appl.
No.: |
08/461,423 |
Filed: |
June 5, 1995 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
992005 |
Dec 17, 1992 |
|
|
|
|
Foreign Application Priority Data
|
|
|
|
|
Dec 27, 1991 [JP] |
|
|
4-346658 |
|
Current U.S.
Class: |
504/359; 514/778;
514/772.2; 514/721; 514/782; 424/485; 514/963; 264/4 |
Current CPC
Class: |
A01N
25/28 (20130101); Y10S 514/963 (20130101) |
Current International
Class: |
A01N
25/28 (20060101); A01N 25/26 (20060101); A01N
025/28 () |
Field of
Search: |
;504/116 ;71/DIG.1
;514/94,132,357,366,473,564,567,649,721,772.2,778,782,963
;424/485 |
References Cited
[Referenced By]
U.S. Patent Documents
|
|
|
3780170 |
December 1973 |
Goodhart et al. |
4230687 |
October 1980 |
Sair et al. |
4244836 |
January 1981 |
Frensch et al. |
4380626 |
April 1983 |
Szejtli et al. |
4462839 |
July 1984 |
McGinley et al. |
4696822 |
September 1987 |
Matsumura et al. |
4790990 |
December 1988 |
Mason et al. |
|
Foreign Patent Documents
|
|
|
|
|
|
|
0 141 509 |
|
May 1985 |
|
EP |
|
38-0325 |
|
Aug 1990 |
|
EP |
|
24-96403 |
|
Jun 1982 |
|
FR |
|
38-16865 |
|
Nov 1989 |
|
DE |
|
58-90502 |
|
May 1983 |
|
JP |
|
20-13610 |
|
Aug 1979 |
|
GB |
|
Other References
Sliwka, "Microencapsulation." Angewandte Chemie International
Edition. 14(8):539-550. 1975. .
Bakan et al. "Part III. Microencapsulation," in Lachman et al, ed.
The Theory and Practice of Industrial Pharmacy, 2nd ed. 1976. .
Szetli "Industrial Applications of Cyclodextrins" Ch. 11 of
Inclusion Compounds, Atwood et al. ed. Academic Pr. pp. 331-389.
1984. .
Pitha et al "Molecular Encapsulation of Drugs by Cyclodectrins . .
." Ch. 5. of Bruck, ed. Controlled Drug Delivery. CRC Pr. pp.
125-148. 1983. .
WPI Acc. No. 73-64756U/43, Patent Abstract of Japan, 48-052943,
(1973). .
WPI Acc. No. 78-44930A/25, Patent Abstract of Japan, 53-052626,
(1978). .
WPI Acc. No. 79-74590B/41, Patent Abstract of Japan, 54-113438,
(1979). .
WPI Acc. No. 83-702944/27, Patent Abstract of Japan, 58-090502,
(1983). .
WPI Acc. No. 83-811970/45, Patent Abstract of Japan, 58-167502,
(1983). .
WPI Acc. No. 89-050475/07, Patent Abstract of Japan, 64-000009,
(1989). .
WPI Acc. No. 90-080951/11, Patent Abstract of Japan, 20-36102,
(1990). .
WPI Acc. No. 77-13719Y/08, Patent Abstract of Japan, 52-003833,
(1977). .
Central Patents Index, Basic Abstracts Journal, Section Ch, Week
8408, 18 Apr. 1984, Derwent Publications Ltd., JP-A-59 007-101,
Abstract. .
Chemical Patents Index, Basic Abstracts Journal, Section Ch, Week
8613, 21 May 1986, Derwent Publications Ltd., JP-A-61 030 502,
Abstract. .
Chemical Patents Index, Documentation Abstracts Journal, Section
Ch, Week 9011, 9 May 1990, Derwent Publications, Ltd., JP-A-02 036
102, Abstract. .
Central Patents Index, Basic Abstracts Journal, Section Ch, Week
7802, Derwent Publications Ltd., JP-A-77 048 180, Abstract, Dec.
1977. .
Lachman et al., The Theory and Practice of Industrial Pharmacy, 2nd
ed. pp. 420-438, "Microencapsulation", (1976). .
The Agrachemicals Handbook "Ferimzone", Aug. 1991..
|
Primary Examiner: Clardy; S. Mark
Attorney, Agent or Firm: Foley and Lardner
Parent Case Text
This application is a divisional of application Ser. No.
07/992,005, filed Dec. 17, 1992.
Claims
What we claimed is:
1. A process for production of an agricultural microcapsule having
a diameter of not more than 50 .mu.m, which comprises an
agricultural active ingredient in gum arabic, the process
comprising: (i) dispersing or emulsifying the agricultural active
ingredient in a solution dissolving gum arabic to give a mixture
wherein the average diameter of a suspended particle in the mixture
is from 0.1 .mu.m to 5 .mu.m; and
(ii) spray-drying the mixture.
2. A process for production of an agricultural microcapsule as
claimed in claim 1, wherein a drying temperature of the spray-dry
is in the range of 50.degree. to 250.degree. C.
3. A process for production of an agricultural microcapsule as
claimed in claim 1, wherein the concentration of gum arabic in the
solution is not more than 50% (W/V).
4. A process for production of an agricultural microcapsule as
claimed in claim 1, wherein the viscosity of the mixture is not
more than 2,000 cp at 25.degree. C.
5. A process for the production of an agricultural microcapsule as
claimed in claim 1, wherein the average diameter of an emulsified
particle in the mixture is in the range of 0.1 to 5.0 .mu.m.
6. A process for production of an agricultural microcapsule as
claimed in claim 1, wherein a weight ratio of the active
ingredient/gum arabic is in the range of 1/100 to 10/1.
7. A process for production of an agricultural microcapsule as
claimed in claim 1, wherein the agricultural active ingredient is
an oil at ordinary temperature.
8. An agricultural microcapsule having a diameter of not more than
50 .mu.m, which is obtained by the process of claim 1, wherein the
agriculturally active ingredient is an oil at ordinary
temperature.
9. An agricultural microcapsule having a diameter of not more than
50 .mu.m, which comprises an agricultural active ingredient in gum
arabic, wherein the agriculturally active ingredient is an oil at
ordinary temperature.
10. An agricultural microcapsule as claimed in claim 9, wherein the
weight ratio of the active ingredient/gum arabic is in the range of
1/100 to 10/1.
11. An agricultural composition comprising:
an agricultural microcapsule having a diameter of not more than 50
.mu.m, which comprises an agriculturally active ingredient in gum
arabic; and
an agriculturally useful carrier, wherein the agriculturally active
ingredient is an oil at ordinary temperature.
12. An agricultural composition as claimed in claim 11, wherein the
weight ratio of the active ingredient/gum arabic is in the range of
1/100 to 10/1.
13. An agricultural composition as claimed in claim 11 which is a
solidified emulsifiable concentrate.
14. An agricultural composition as claimed in claim 11 which is a
solidified emulsifiable concentrate comprising:
(i) 5.0 to 60 wt % of an agricultural oily active ingredient;
(ii) 10.0 to 94.6 wt % of gum arabic;
(iii) 0.2 to 20 wt % of surfactant having HLB of 2 to 8; and
(iv) 0.2 to 10 wt of surfactant having HLB of 10 to 19, wherein the
active ingredient and both of the surfactants are in the gum
arabic.
15. An agricultural composition as claimed in claim 11 which is DL
dust.
16. An agricultural composition as claimed in claim 11 which is DL
dust comprising:
(i) 0.5 to 20 wt % of an agricultural microcapsule having a
diameter of not more than 50 .mu.m, which comprises an
agriculturally active ingredient in gum arabic, wherein the
agriculturally active ingredient is an oil at ordinary
temperature;
(ii) 0 to 10 wt % of an active ingredient which is incompatible to
the active ingredient in the microcapsule;
(iii) 63.8 to 99.28 wt % of solid carrier;
(iv) 0.1 to 1.0 wt % of coagulant;
(v) 0.02 to 0.2 wt % of antioxidant; and
(vi) 0.1 to 5.0 wt % of anti-blocking agent, wherein diameter of
the DL dust is in the range of 5 to 50 .mu.m.
Description
The present invention relates to a novel agricultural microcapsule
with improved physical and chemical properties which comprises an
agricultural active ingredient, and production thereof.
[BACKGROUND OF THE INVENTION]
In general, pesticidal compositions include those containing a
single pesticidal active ingredient and those containing two or
more pesticidal ingredients. The former is expected to show a
single effect. On the other hand, the latter compositions are
expected to show superior effects to those shown by the individual
ingredient, or labor-saving application. Particularly, the
admixture containing two or more pesticidal active ingredients has
been widely and generally used in the agricultural field. These
single or mixed agricultural compositions usually are subjected to
a long period after production before usage. During the period, the
active ingredients in the composition may be decomposed, and
accordingly the composition may lose its biological activity and
sometimes may cause phytotoxicity.
For example,
(Z)-2'-methylacetophenon.dbd.6-dimethylpyrimidin-2-ylhydrazone
(hereinafter referred to as ferimzone) is known as an excellent
agricultural fungicide which shows strong fungicidal activity for a
wide range of plant pathogenic fungi such as Pyricularia oryzae,
Cochliobolus miyabeanus, etc. (cf. Japanese Patent Publication No.
21551/1986). For control of rice stem bores, leaf hoppers, etc., it
is well known that organophosphorus compounds such as
0,0-dimethyl-0-(3-methyl-4-nitrophenyl)phosphorothioate
(hereinafter abbreviated to fenitrothion) and the like are
effective. Accordingly, it is strongly expected to develop an
admixture having biological activities of both of said two
compounds. However, when the two compounds are mixed, the active
ingredients are remarkably decomposed, after a long period of
storage, and the admixture shows no biological activity.
Especially, organophosphorus compounds are more decomposed with the
passage of time. For control of such decomposition, agricultural
compositions containing boron oxide and/or boron oxide complex are
known (Japanese Patent Laying-Open No. 9/1989). However, boron
oxide, a stabilizer, itself is very hygroscopic, and thus the
physical stability of this preparation is not much improved.
An admixture of 5-methyl-1,2,4-triazolo[3,4-b]benzothiazole
(hereinafter abbreviated to tricyclazole), which is a fungicide
showing excellent effect on control of blast disease, etc., and an
insecticidal organophosphorus compound such as fenitrothion is
known. However, when the two compounds are admixed together, said
two ingredients react with each other, resulting in chemical change
and decomposition, and finally the composition shows no effective
biological activity. Thus, for control of decomposition of the
admixture containing tricyclazole and organophosphorus compound, an
agricultural composition containing oxalic acid and/or
benzenesulfonic acid is well known (Japanese Patent Laying-Open No.
167502/1983). Moreover, for saving labor, an admixture containing
tricyclazole and fenitrothion as well as validamycin A in order to
simultaneously control slimy brown rot of rice plant is expected to
be developed. For such mixture, benzensulfonic acid which is added
to control decomposition of tricyclazole and fenitrothion
disadvantageously decomposes validamycin A.
Recently, the development of agricultural admixture has acquired
greater importance. However, some agricutural active ingredients
are unstable under acidic conditions, while others are unstable
under basic conditions. That is, the characteristics of active
ingredients are generally different, and the methods to
sufficiently stabilize active ingredients in admixture have not
been developed.
For sufficient demonstration of the effect of the active
ingredients in the agricultural preparations, particularly dust
when applied as to plants, it is also important to improve
dispersibility of such dust for effective and homogeneous
application of the dust to plants.
However, for an admixture containing liquid agricultural active
ingredients, physical properties such as flowability and
dispersibility of the dust preparation may be deteriorated,
accordingly, the preparation can not be sprayed homogeneously,
resulting in bad effect and sometimes causing phytotoxicity.
Considering such conditions, methods to improve physical properties
by adding fine powder of aerosil, white carbon etc. have been
employed. However, in such methods, improvement of the physical
properties of the preparation is difficult with more liquid
content. Accordingly, study to improve physical properties of the
preparation has been carried out. For example, dust composition
containing one or more organophosphorus salts or ester (cf.
Japanese Patent Laying-Open No. 113438/1979), dust composition for
gardening containing polysiloxane (cf. Japanese Patent Laying-Open
No. 90502/1983) and the like are known. However, effective methods
for improvement of physical and chemical properties of the
effective preparation of mixture containing more liquid active
ingredients have not been attained.
The preparation in which an active ingredient was coated by wax was
also provided in the prior art. But as wax is insoluble to water,
it is very hard to control the release of the active ingredient
from the preparation. Moreover, a preparation containing fine
granules as powder cannot be provided by such a conventional
method.
Accordingly, in the above-mentioned conventional methods,
stabilization of pesticidal active ingredients has not been
attained in a mixture of ferimzone and fenitrothion, a mixture
containing tricyclazole and fenitrothion or other pesticide mixture
preparations. Further, no improvement of the effective physical and
chemical properties of a mixture containing liquid pesticidal
active ingredients has been attained.
The processes for production of agricultural preparations by spray
drying are described in, for example, Japanese Patent Laying-Open
Nos. 52626/1978, 52948/1973 and 64904/1985). These references
disclose processes for production to obtain granules of relatively
large particle size by spray drying slurry wherein agricultural
active ingredients coexist with solid carrier.
Preparations for solidifying a liquid agricultural ingredient such
as an active ingredient have been prepared by impregnating or
adsorbing the ingredient with a solid carrier. The above-mentioned
preparation produced by spray-drying is also proposed with the
object of impregnating or adsorbing an active ingredient with a
solid carrier just by means of spray-drying. No conception to
solidify an active ingredient itself is in the prior art. No solid
preparation as powder is obtained by such a conventional method.
Therefore, adversed problems have not solved sufficiently yet. Such
problems are that imcompatible ingredients such as active
ingredients, carriers, diluents, etc. interact each other and that
the active ingredient is decomposed itself.
On the other hand, capsule preparations in the fields of medicines,
perfumery or feed additive have been known (U.S. Pat. No.
4,230,687; Japanese Patent Laying-Open Nos. 24347/1986, 55816/1974,
69039/1985: Yoshiaki KAWASHIMA "Fine Particle Design-Technology",
pub. by Powder and Industry Co., pp.86-96 (1988)). However, the
above conventional methods have not discribed encapsulation of an
agricultural active ingredient at all. In addition, there is no
disclosure on whether or not the encapsulated pesticide can be
effective in the field if an agricultural active ingredient were
encapsulated according to the conventional method. Only Japanese
Patent Laid-open No. 36102/1990 proposes a pesticidal admixture
containing a microcapsulated active ingredient of average particule
size of not more than 100 .mu.m and powdery additive. In a
specification of the patent application, however, there are only
disclosures of conventional coating materials including
water-soluble and water-insoluble ones, and no disclosure on what
kind of microcapsules were obtained or used. How to make them also
could not be found. It must be clarified that there is no
investigation and no motivation on a microcapsule including
water-soluble coating material in the prior application.
Accordingly, the prior art has not solved the problems of
stabilization of the individual active ingredients and
stabilization of incompatible compounding agents. Further, they
provide no suggestion whether their technique can be applied for
agricultural compositions.
[SUMMARY OF THE INVENTION]
The present invention solves such problems of the aforementioned
conventional technique and provides an agricultural microcapsule
wherein the active ingredients are stabilized. The microcapsule can
be admixed with the other ingredient even if the other is
incompatible to the active ingredient comprised in the
microcapsule. The microcapsule provided in this invention is
handled easily and has a good adhesiveness to a plant. Specially,
when an active ingredient is a liquid such as oil, the active
ingredient per se can be handled as a solid powder by means that
the active ingredient is microencapsulated according to the present
invention.
Further, the present invention provides an agricultural composition
comprising the agricultural microcapsule, Especially, DL dust
(Drift-Less) and solidified emulsifiable concentrate which are
easily handled can be provided in the present invention.
Still further, the present invention provides an agricultural
admixture composition comprising two or more agricultural active
ingredients which are incompatible each other, by means that at
least one active ingredient is microcapsulated according to the
present invention.
Moreover, the present invention provides an useful process for
production of the microcapsule which is spray-drying.
[DETAILED DISCRIPTION OF THE INVENTION]
The present inventors have studied intensively to obtain
agricultural preparations comprising one or more agricutural active
ingredients wherein decomposition of the active ingredients is
controlled without any adverse effect on other ingredients. As a
result, the study focused on the agricultural active ingredient
itself and found that the agricultural active ingredients are
microencapsulated to a particular diameter with water-soluble
materials such as gum arabic or .alpha.-cyclodextrin to improve
their stability and further to improve physical and chemical
properties of the preparations comprising said ingredients.
According to further studies, we have achieved the present
invention.
The present invention relates to an agricultural microcapsule of
particular diameter of not more than 50 .mu.m comprising
agricultural active ingredients in water-soluble coating materials,
an agricultural composition comprising the microcapsule, and
production thereof.
The agricultural active ingredients may be either oily or solid.
The solid ingredients include water-soluble type and
water-insoluble type. Both types can be used for the present
invention. Accordingly, the present invention can be applied to
known insecticides, miticides, fungicides, herbicides, and any
other active ingredients as pesticides.
Especially, the present invention advantageously enables
solidifying of oily ingredients. Accordingly, the oily ingredients
can be used like the conventional powder. In the present
microcapsule, as the active ingredient is covered with
water-soluble coating materials, interaction such as
incompatibility may be controlled when the microcapsule is used as
an admixture. It is hard for an active ingredient to appear on the
surface of the microcapsule of the present invention.
The fungicides and insecticides which can be used for the present
invention will be shown below. Symbols "S" and "L" show that
ingredients marked "S" are soild at room temperature (1.degree. to
30.degree. C.) and "L" are liquid or oily.
Carbamate insecticides:
propoxur(S), isoprocarb(S), BPMC(S), xylylcarb(S), metolcarb(S),
XMC(S), ethiofencarb(L), carbaryl(S), pirimicarb(S), bendiocarb(S),
carbofuran(S), furathiocarb(L), carbosulfan(L), aminosulfulan,
methomyl(S), cartap(S), fenoxycarb(S), alanycarb(S),
cloethocarb(S), benfuracarb(L), fenothiocarb(S), etc.
Organophoshporus insecticides:
fenthion(L), fenitrothion(L), propaphos(L), cyanophos(L),
prothiofos(L)., sulprofos(L), profenofos(L), EPN(L),
cyanofenphos(S), acephate(S), oxydeprofos(L), disulfoton(L),
thiometon(L), phenthoate(S), malathion(L), dimethoate(S),
vamidothion(S), mecarbam(L), trichlorophon(S), naled(L),
dichlorvos(L), chlorofenvinphos, tetrachlorvinphos(S),
monocrotophos(S), phosalone(S), dialifos(S),
chlorpyrifos-methyl(S), chlorpyrifos(S), pirimiphosmethyl(L),
diazinon(L), etrimfos(L), pyridaphenthion(S), quinalphos(S),
isoxathion(L), methidathion(S), salithion(S), pyraclophos(L),
chlorthiophos(L), fortress(L), isofenphos(L), butathiofos, EDDP(L),
etc.
Pyrethroids insecticides:
cyfluthrin(L), permethrin(L), cypermethrin(S), deltamethrin(S),
cyhalothrin(L), fenpropathrin(S), fenvalerate(L), flucythrinate(L),
flubalinate, ethofenprox(S), silanophane, fenpropathrin(S),
tralomethrin(S), cycloprothrin(L), acrinathrin(S). etc.
Urea insecticides:
difulbenzuron(S), chlorfluazuron(S), nomolt(S), hexaflumuron(S),
flufenxuron(S), diafenthiuron, flucycloxuron(S). hexythiazox(S),
etc.
Other insecticides:
thiocyclam(S), buprofezin(S), bensultap(S), imidacloprid(S),
hydroprene(S), fenazoquin, clofentezine(S), levamisol(S),
dienochlor(S), cyromazine(S), fenpyroximate, pyridaben(S),
pyriproxyfen(S), sufluramid, thiodicarb(S), nitenpyram(S),
1-(2-chloro-5-thiazolylmethyl)-3-methyl-2-nitroguanidine, etc.
Carbamate fungicides:
zineb(S), maneb(S), benomyl(S), thiophanate-methyl(S),
cypendazole(S). carbendazim(S), prothiocarb(S), diethofencarb(S),
etc.
Antibiotic fungicides:
validamycin A(S), kasugamycin(S), avermectin(S), milbemycin(S),
etc.
Anilide fungicides:
mepronil(S), flutoluanil(S), pencycuron(S), carboxin(S),
oxycarboxin(S), pyracarbolid(L), mebenil(S), furcarbanil,
cyclafuramid(S), benodanil(S), granovax, metalaxyl(S), ofurace(S),
benalaxyl(S), oxadixyl(S), cyprofuram(S), clozylacon, metsulfovax,
tecloftalam(S), etc.
Organophosphorus fungicides:
edifenphos(L), IBP(L), pyrazophos, aliette, tolclofosmethyl(S),
etc.
Azole fungicides:
fenarimol(S), flurprimidol(S), fluotrimazole(S), triadimefon(S),
triadimenole(S), diclobutazol(S), paclobutazol, diniconazole(S),
uniconazole(S), triflumizole(S), propiconazole(L), flutriafol(S),
flusilazole(S); penconazole(S), prochloraz(S), triapenthenol(S),
triarimol(S), fenarimol(S), bitertanol(S), imazalil(L),
etaconazole(S), paclobutrazol(S), phenapronil, viniconazole,
difenoconazole, bromuconazole, myclobutanil(S), hexaconazole(S),
cyproconazole, furconazole-cis(S), fenethanil, tebuconazole(S),
etc.
Dicarboxyimide fungicides:
dichlozoline(S), iprodione(S), vinclozolin(S), procymidone(S),
myclozolin, fluoroimide(S), etc.
Other fungicides:
fthalide(S), monguard.RTM.(S), isoprothiolane(S), tricyclazole(S),
probenazole(S), ferimzon(S), fluazinam(S), butiobate(L),
pyroquilon(S), chlobenazone, TPN(S), captan(S), captafol(S),
folpet(S), thiabendazole(S), fuberidazole(S), tridemorph(L),
fenpropimorph(L), triforine(S), ethirimol(S), dimethirimol(S),
hymexazol(S), ethazol(L), fenpropidin, pyrifenox(L),
dilmethomorph(S), fenpiclonil, zarilamid, triclamide(S),
flusulfamide, befran(S), dimfluazole, oxolinic acid(S), proxychlor,
etc.
Pheromone:
okimeranolure(S), cherrytlure(L), diamolure(L), etc.
Other insecticides and fungicides:
fipronil, novaluron, flufenprox, fenpyrad or tebufenpyrad,
methoxadiazone, benfluthrin, pyriproxyfen(S), diafenthiuron,
dichlorfluanid, ftalaxyl, flapenazole, pipanipirim, thicyofen,
opus.RTM., ipconazole, dimetconazole, myxothiazol, thioimiconazole,
quinconazole. etc.
Herbicides which can be used for the present invention will be
shown below:
atrazine(S), cyanazine(S), ametryn(S), alachlor(S), butachloor(L),
metolachlor(L), IPC(S), CIPC(S), thiobencarb(L), butylate(L),
EPTC(L), dicamba(S), monuron(S), diuron(S), fluometuron(S),
chloroxuron(S), benzthiazuron(S), karbutilate(S), metoxuron(S),
methabenzthiazuron(S), chlorotoluron(S), isoproturon(S),
trifluralin(S), pendimethalin(S), 2,4-D(S), MCPA(S), MCPP(S),
molinate(L), epronaz(S), sethoxydim(L), alloxydim(S), tralkoxydim,
fluazifop-butyl(L), quizalofop ethyl(S), fenoxaprop-ethyl(S),
haloxyfop ethoxyethyl(S), fluazifop-P-butyl(L),
framprof-M-isopropyl, tridiphane(S), methazole(S), oxadiazon(S),
bentazone(S), pyrazolate(S), chlormethoxynil, chlornitrofen(S),
dichlofop- methyl, oxyfluorfen(S), lactofen(L), achonifen(S),
propanil(S), metribuzin(S), acifluorfen(S), fomesafen(S),
bensulfuron methyl(S), chlorsulfuron(S), chlorimuron methyl(S),
primisulfuron-methyl(S), triasulfuron(S), imazaquin(S),
imazamethabenz(S), imazethapyr(S), tribenuron methyl(S),
benzoylprop-ethyl(S), difenzoquat(S), Ioxynil(S), bifenox(S),
clopyralid(S), mecoprop(S), metsulfuron-methyl(S), fluroxypyr(S),
isoxaben(S), tiameturon-methyl, fluoroglycofen-ethyl(S),
bromoxynil(S), pendimethalin(S), prometryn(S),
pyrazosulfuron-ethyl(S), piperophos(L), esprocarb(L),
pyributicarb(L), dithiopyr(S),
HW-52(2',3'-dichloro-4-ethoxymethoxybenzanilide:S), benzofenap(S),
benoxazol(L), bromobutide(S), chlomeprop, chlorthiamid(S),
dalapon(L), dimepiperate(S), fluothiuron(S), chlornitrofen(S),
MCPB(S), MCPCA, mefenacet(S), methoxyphenone(S), naproanilide(S),
nitrofen(S), phenopylate(L), pyrazoxyfen(S), simetryn(S), swep(S),
sinosulfuron, etc.
The water-soluble coating material used in the present invention
means those readily soluble in water. Particularly, a water-soluble
coating material having low crystallinity and a sp value of 5 to
40, preferably 10 to 30, is used. The sp value is generally
well-known as a solubility parameter which shows an approximation
between solute's polarity and solvent's. More preferbaly a
water-soluble coating materials having a film-forming and/or
clathrate activity are used.
Such materials include cyclodextrins and water-soluble polymers
such as a water-soluble natural polymer, a water-soluble
semi-synthetic polymer, a water-soluble synthetic polymer and the
like.
Examples for the water-soluble natural polymer include starches,
mannans, extracts from seaweeds, viscous substances from plants or
microorganisms proteins, etc. The starches are exemplified as sweet
potato starch, potato starch, tapioca starch, wheat starch, corn
starch, etc. The mannans are exemplified as konjak mannan, etc. The
extracts from seaweeds are exemplified as funori, agar, sodium
alginate, etc. The viscous substances of plants are exemplified as
Abelmoschus manihot, tragacanth gum, arabic gum, etc. The proteins
are exemplified as glue, gelatin, casein, collagen, etc. Among
those, water-soluble natural polymers such as viscous substances of
plants are preferable, for example, arabic gum. The arabic gum is a
water-soluble polysaccharide from Acacia senegal, Acasia seyal and
the same kinds of plants, which has arabinose as a main element in
its molecule.
Examples for the synthetic water-soluble polymer include polyvinyl
alcohol, polyethylene oxide, polyacrylamide, sodium polyacrylate,
polyvinyl pyrollidone, copolymer of methyl methacrylate, butyl
methacrylate and dimethylaminoethyl methacrylate (Eudragit.RTM.),
polycaprolactam, etc.
Examples for the semi-synthetic water-soluble polymer include
water-soluble semi-synthetic celluloses, water-soluble
semi-synthetic starches, etc. The water-soluble semi-synthetic
celluloses are exemplified as viscose, methylcellulose,
ethylcellulose, hydroxyethylcelllulose, carboxymethylcellulose,
hydroxypropylcellulose, hydroxypropylmethylcellulose, etc. The
water-soluble semi-synthetic starches are exemplified as
water-soluble starch, carboxymethylated starch, dialdehyde-starch,
dextrin, oxidized starch, etherified starch, esterified starch,
etc. Among those, water-soluble semi-synthetic starches are
preferable, for example, dextrin. Generally the detxrin includes
four types of amylodextrin, erythrodextrin, achrodextrin and
maltodextrin. All of those detxrins or mixtures thereof can be used
in the present invention when they are water-soluble. As
amylodextrin is in fact slightly soluble in cold water, the
proportion of its content prefers to be lower. Preferrably
erythrodextrin, achrodextrin, maltodextrin and a mixture containing
mainly erythrodextrin and/or achrodextrin are used.
Molecular weight and degree of polymerization of the
above-mentioned water-soluble polymers must not be limited, and
should be determined according to kinds of monomers composing the
polymer and to properties of the polymer itself. As mentioned
before, any water-soluble coating materials can be used in the
present invention when they are soluble in water and have
film-forming activity. For example, in the case of dextrin, its
molecular weight of not more than 10,000 is standerd and its range
of 3,000 to 10,000 is preferable. Erythrodextrin and achrodextrin
are preferred dextrins. In the case of polyvinyl alcohol, its
average degree of polymertization of 300 to 3,000 is standard and
its ragne of 300 to 2,000 is preferable. Particulary, in addition
to that, its saponification ratio of 80 to 99 mol % is useful,
preferrably 85 to 95 mol %. In the case of arabic gum, its
molecular weight of 150,000 to 600,000 is standard, preferrably
240,000 to 580,000.
Examples for the cyclodextrins include .alpha.-, .beta.-,
.tau.-cyclodextrins, etc. Among those, .alpha.-cyclodextrin is
preferable. Commercialized products are Toyoderin.RTM.(manufactured
by TOYO JOZO Co., Ltd.: containing 50% of cyclodextrins, specially
30% of .alpha.-cyclodextrin), Isoelite.RTM.(manufactured by Nikken
Chemical Co., Ltd.: containing 60% of .alpha.-cyclodextrin),
etc.
The above-mentioned water-soluble coating materials can be mixed
each other to be adopted to the present invention. Generally,
supply of a natural polymer is precarious as its output is greatly
affected by changes of climate. On the other hand, a synthetic
polymer is preferable from a view point of its constant supply.
Therefore, a mixture of water-soluble natural polymers and the
other polymers is sometimes used. For example, mixtures of
polyvinyl alcohol as a water-soluble synthetic polymer and arabic
gum as a water-soluble natural polymer or dextrin as a
water-soluble semi-synthetic polymer can be used in the present
invention. In such cases, the proportion of synthetic polymers/the
other polymers is not more than 2/1 (weight ratio), preferably in a
range of 1/50 to 1/1.
Among the aforementioned materials, water-soluble natural polymer
gum of viscous substance of plants, water-soluble semi-synthetic
starches and cyclodextrin are preferable as a water soluble coating
material. The concrete examples are arabic gum,
.alpha.-cyclodextrin and dextrin. Specially, the most preferable
water-soluble coating material is water-soluble natural polymer gum
of viscous substance of plants such as arabic gum.
The ratio of the above agricultural active ingredient to the
water-soluble material is 1/100 to 10/1 (by weight). Preferably, it
is in the range from 1/20 to 5/1.
At such ratio, the diameter of the microcapsule comprising
agricultural active ingredients in water-soluble coating materials
is not larger than 50 .mu.m. Preferably, the diameter is 3 to 45
.mu.m, more preferably 5 to 40 .mu.m.
The microcapsule having a diameter of not less than 50 .mu.m has
bad adhesion to plants as a dust formulation and fails to show the
effect of the active ingredients. Further, when mixed with other
active ingredients, a remarkable difference in density results in
difficulty in sufficient mixing. On the other hand, the
microcapsule comprising very fine particles of diameter of the
order of 0 to 3 .mu.m may drift away when sprayed, causing
phytotoxicity and giving adverse effects to human bodies. As
preparations aiming at prevention of such drift, DL (Drift-Less)
dust has been known. For this purpose, as shown in the preferable
embodiment of the present invention, dust formulation having a
diameter of granule within the range from 3 to 45 .mu.m, more
preferably from 5 to 40 .mu.m should be selected.
The production of the agricultural microcapsule of the present
invention may be carried out according to the following
processes:
1) Preparation of an aqueous solution, a suspension or an emulsion
of the agricultural active ingredient and water-soluble coating
material
In general, the agricultural active ingredients are added to an
aqueous solution of the water-soluble coating material. Using an
emulsifier and stirrer, an aqueous solution, a suspension or an
emulsion is prepared. The usable devices include a homomixer, a
microfluidizer, a three-one motor, a die mill, etc. Such agitation
may be carried out while heating if desired.
When the agricultural active ingredients are water-soluble, the raw
powder may be directly dissolved to prepare an aqueous solution.
When said active ingredients are water-insoluble, the raw materials
may be ground to the powder having an average particle diameter of
0.1 to 10 .mu.m, preferably 0.2 to 5 .mu.m and a suspension is
prepared. When the active ingredients are oily, they are prepared
into an emulsion.
The amount of water used in this step may be optionally determined
depending on the types of the water-soluble material or the active
ingredients used. The amount is selected so that the concentrations
of the water-soluble material and the active ingredients are not
too high to become an obstacle of the following drying step. In
general, the concentration of the water-soluble material is not
more than 50%(W/V), preferably in the range of 2 to 50%(W/V). The
viscosity of the resulting aqueous solution, suspension or emulsion
is not more than 2,000 cp (25.degree. C.), preferably not more than
1,000 cp.
The suspension or the emulsion may be produced to give the average
particle diameter of the suspended particles or emulsified
particles of 0.1 to 5 .mu.m, preferable 0.2 to 3 .mu.m.
Particularly for production of an emulsion, desired emulsified
particles are obtained by shearing and agitation.
2) Drying of the prepared solution
The solution prepared in the above step (1) is dried by suction
drying or spray drying.
When drying is carried out by means of suction drying or the like,
the dried product is ground and screened into particles smaller
than a particular diameter.
Spray drying is effective to obtain microcapsule of its diameter
within the given range. When drying is carried out by means of
spray drying using a spray drier or the like, the drying conditions
are optionally selected to give the product with the desired
diameter. The temperature of spray-drying is in the range to be
capable of removing water as a solvent from the solution prepared
in the step (1). For example, drying step is carried out at the
range of 50.degree. to 250.degree. C., preferably 70.degree. to
200.degree. C. The rotation speed of atomizer of a spray-dryer is
instituted into the range to be capable of having the diameter of
the obtained microcapsule be not more than 50.mu.m, preferably in
the range of 3 to 45.mu.m, more preferably 5 to 40 .mu.m.
More concrete example in which a spray-dryer L-8 type (manufactured
by Okawara Kakoki Co.) is used is shown below. Emulsion, suspension
or solution prepared in the step (1) is dried by hot air at
180.degree. C. of inlet-temperature and at 110.degree. C. of
exit-temperature with rotation speed of the atomizer of 30,000rpm
and the flow rate of the hot air of 30ml/min, to obtain
microcapsules having a diameter of not more than 50.mu.m. But the
drying condition must not be limited to those mentioned above.
Generally, the exit-temperature should be not less than 100.degree.
C. in order to avoid an adverse effect in that residual water in
the obtained microcapsules may have a bad influence on stability of
an active ingredient.
The microcapsule of the present invention can be obtained as shown
above. Such microcapsule may contain necessary additives other than
the agricultural active ingredients and the water-soluble coating
materials. For example, a stabilizer characteristic of a certain
kind of active ingredients may be added with the active ingredients
to the solution prepared in the above step (1). Any agricultural
active ingredients can be simultaneously subjected to the above
steps (1) and (2) to give the microcapsuleof the present invention
so long as said ingredients are not interactive.
Thus obtained microcapsule can be prepared to give an agricultural
composition in the same manner as that of the conventional
pesticidal powder.
The preparation using such agricultural composition includes, for
example, dusts, DL dust, solified emulsifiable concentrate,
water-dispersible powder, water-dispersible granules, seed
treatment agent, particulate F. Particulary the microcapsule of the
present invention can be effectively used for DL dust and
solidified emulsifiable concentrate.
To prepare an admixture comprising two or more agricultural active
ingredients, each of ingredients may be admixed together as a
microcapsule of the present invention. Alternatively, a certain
ingredient is solely adopted as microcapsule of the present
invention. Particularly, when the oily active ingredient is
admixed, said oily ingredient is microcapsulated according to the
present invention to advantageously enable formulation by simple
operation of powder mixing. When incompatible ingredients are
admixed either ingredient is formed into the microcapsule of the
present invention to enable formulation by simple operation of
powder mixing controlling interaction due to said
incompatibility.
Particulary, when the productions for admixtures of fenitrothion
& ferimuzone, ferimuzone & cartap.hydrochloride,
tricyclazole & fenitrithion, bensultap & BPMC, methomyl
& cartap.hydrochloride and EDDP & pencycron, microcapsules
of the present invention are useful. In these cases, it is
preferable that an oily ingredient such as fenitrothion and an
unstable ingredient should be microcapsulated according to the
present invention, and then the microcapsules are admixed with the
other ingredients.
The solid agricultural preparation itself may be produced by the
known method. These preparations may comprise an agricultural
auxiliary ingredients such as a dispersant, a spreader, a wetting
agent, a thickener, a consolidation inhibitor, a coagulant, a
binder, an antioxidant, a dewatering agent, etc., if desired.
As the conventional solid carrier and filler, one or more of the
following materials and the like may be admixed:
1) mineral powder: clay (clay dust, kaolin, bentonitc, Jaoanese
acid clay, fuller's earth, etc.), talc (talc powder, agalmatolite
powder, etc.), silica (diatomaceous earth powder, mica powder,
etc.)
2) vegetable powder: soybean meal, tobacco powder, flour, wood
meal, etc.
3) calcium carbonate, sulfur powder, urea powder, etc.
As the surfactant used as a dispersant, a spreader, a wetting agent
or a penetrant, one or more nonionic or anionic surfactants may be
admixed and used.
For example,
nonionic surfactant
polyoxyethylene alkylaryl ether (Neugen EA-142.RTM., HLB 14:
manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.)
block copolymer of ethylene oxide and propylene oxide (Newpole
PE-64.RTM.: manufactured by SANYO CHEMICAL INDUSTRIES, LTD),
etc.
The HLB value of the nonion surfactant is preferably in the range
of 8 to 18, more preferably 10 to 15.
anionic surfactant
polycarboxylic acid surfactant (Toxanone GR-30.RTM.; manufactured
by SANYO CHEMICAL INDUSTRIES, LTD)
dialkylsulfosuccinate ester sodium salt (Neocol SW-C.RTM.;
manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.)
sodium alkylnaphthalenesulfonate (Newcargen BX-C.RTM.; manufactured
by Takemoto Yushi)
polyoxyethylene distyrenated phenyl ether sulfate ammonium salt
(Dixzole 60A.RTM.; manufactured by Dai-ichi Kogyo Seiyaku Co.,
Ltd.)
sodium lignin sulfonate
potassium lignin sulfonate and the like.
Such surfactant is generally used in the range from 0 to 30 wt %,
preferably from 0 to 20 wt % relative to the total amount of the
preparation.
As fluidized auxiliaries, PAP auxiliary (isopropyl acid phosphate,
etc.), talc and the like may be used. Such fluidizing auxiliaries
are generally used within the range from 0 to 20 wt % preferably
from 0 to 10 wt % relative to the total amount of the
preparation.
As an anti-blocking agent, white carbon, diatomaceous earth,
magnesium stearate, aluminum oxide, titanium dioxide, magnesium
oxide, zinc oxide or the like may be used. Such anti-blocking agent
is generally used within the range from 0 to 50 wt %, preferably
from 0 to. 20 wt % relative to the total amount of the
preparation.
As a coagulating agent, liquid paraffin, ethylene glycol,
diethylene glycol, triethylene glycol, isobutylene polymer (IP
solvent-2835.RTM.; Manufactured by Idemitsu Petroleum Chemical Co.)
or the like may be used. Such coagulating agent is generally used
within the range from 0 to 20 wt %, preferably from 0.2 to 10 wt %
relative to the total amount of the preparation.
As a binder, sodium carboxymethylcellulose, dextrin,
.alpha.-starch, polyvinyl alcohol, sodium lignin sulfonate,
potassium lignin sulfonate, or the like may be used. Such binder is
generally used within the range from 0 to 30 wt %, preferably from
0.2 to 10 wt % relative to the total amount of the preparation.
As an antioxidant, dibutylhydroxytoluene,
4,4-thiobis-6-tert-butyl-3-methylphenol, butylhydroxyanisole,
p-octylphenol, mono-(di- or tri-)methylbenzylphenol,
2,6-tert-butyl-4-methylphenol,
pentaerythritol-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)]propionate
or the like may be used. Such antioxidant is generally used within
the range from 0 to 30 wt %, preferably from 0 to 10 wt % relative
to the total amount of the preparation.
As a desiccating agent, anhydrous gypsum, silicagel powder or the
like may be used. Such desiccating agent is generally used within
the range from 0 to 30 wt %, preferably from 0.5 to 20 wt %
relative to the total amount of the preparation.
As ultraviolet absorbent,
2-(2'-hydroxy-5'-methylphenyl)benzotriazole,
2-ethoxy-2'-ethyloxazalic acid bisanilide, succinic acid
dimethyl-1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine
polycondensate or the like may be used. Such ultraviolet absorbent
is generally used within the range from 0 to 20 wt %, preferably
from 0.5 to 10 wt % relative to the total amount of the
preparation.
As UV ray scattering agent, titanium dioxide or the like may be
used. Such UV ray scattering agent is generally used within the
range from 0 to 90 wt %, preferably from 1.0to 20 wt % relative to
the total amount of the preparation.
Thus obtained solid preparation of various kinds may be sprayed and
applied by the method according to the known method according to
usage of the active ingredients contained therein.
Prescription of typical DL dust is shown below.
The agriculutural microcapsule 0.5 to 20 wt %
The other agricultural active ingredients 0 to 10 wt %
Solid carrier for DL dust 63.8 to 99.28 wt %
Coagulating agent 0.1 to 1.0 wt %
Antioxidant 0.02 to 0.2 wt %
Anti-blocking agent 0.1 to 5.0 wt %
The above-mentioned solid carrier for DL dust is clay for DL dust,
kaolin, bentonite, diatomaceous earth powder, mica powder,
agalmatolite powder and the like. The coagulating agent is liquid
paraffin, ethylene glycol, isobutylene polymer (IP
solvent-2835.RTM.; Manufactured by Idemitsu Petroleum Chemical
Co.), polybutene and the like. The antioxidant is
dibutylhydroxytoluene, 4,4-thiobis-6-tert-butyl-3-methylphenol,
butylhydroxyanisole,
pentaerythritol-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)]propionate
and the like. The anti-blocking agent is white Carbon, diatomaceous
earth, magnesium stearate, aluminum oxide, titanium dioxide,
magnesium oxide, zinc oxide and the like. The active ingredients
for a paddy field are effective. The active ingredient is used
alone or as a mixture. For example, fenitrothion, tricyclazole,
ferimzone, validamycine A, cartap.hydrochloride, fthalide,
ethofenprox, bensultap, buprofezin, isoprothiolane. BPMC are used.
Specially agricultural admixtures of ferimuzone & fenitrothion,
fenitrothion & tricyclazole and ferimuzone &
cartap.hydrochloride are effective. In such cases. ferimuzone and
fenitrothion should be microcapsulated according to the present
invention. The particule size of the obtained DL dust is in the
range of 5 to 50 .mu.m, preferably 10 to 50 .mu.m.
By using the obtained DL dust, decomposition of an active
ingredient can be controlled easily. The DL dust can be stored for
a long term. An oily active ingredient can be solidified as powder
according to the presnt invention and the powder preparation has an
improved physical and chemical properties. As a results, the
obtained DL dust can be easily scattered to an agricultural field
evenly. Moreover, as a water-soluble coating material is used as a
coating substance for microcapsules, the DL dust's adhesiveness to
plants is extremely improved, and its biological activity can be
enhanced.
Prescription of typical solidified emulsifiable concentrate is
shown below.
Oily active ingredient 5.0 to 60 wt %
Water-soluble coating material 10.0 to 94.6 wt %
Surfactant (HLB: 2 to 8) 0.2 to 20 wt %
Surfactant (HLB: 10 to 19) 0.2 to 10 wt %
As the above mentioned surfactants nonionic surfantants are used.
Particulary, both of one of HLB 2 to 8 and the other of HLB 10 to
19 are preferably used jointly. The one of HLB 2 to 8 is sorbitan
alkylate, polyoxyethylene nonylphenylether or the like. The one of
HLB 10 to 19 is polyoxyethylene alkylarylether, polyoxyethylene
sorbitan mono-oleate, polyoxyethyelene lanoline alcohole ether or
the like. The active ingredients for a paddy field are useful. The
active ingredient is used alone as a mixture. Oily active
ingredients such as pyraclofos, fenitrothion, ethofenprox,
malathion, PAP, propaphos, IBP and the like are used. Microcapsules
of the present invention can be applied as solidified emulsifiable
concentrate itself. The concentrate can be prepared by emulsifying
the above-mentioned composition with water and spray-drying it
according to the present invention. In this case, arabic gum is
preferred as water-soluble coating materials. Diameter of the
Solidified emulsifiable concentrate is in the range of 10 to 50
.mu.m. preferably 20 to 50 .mu.m.
As the concentrate can be prepared without organic solvent, its
safety for human and environment is exceed. The concentrate can be
wrapped without using a glass bottle, merely by using a paper bag
or the like. Thereofre, a serious environmental problem such as
waste of packages for conventional emulsifiable concentrates is
solved by the present invention. When water-soluble film is used as
a package for the concentrate, emulsion for scattering is easily
prepared without directly contacting chemicals as pesticide. Such a
way is also very safe for an operator.
The solid agricultural preparation obtained as mentioned before can
be applied or scattering to an agricultural field according to a
conventional method determined by the active ingredients comprised
in it.
The agricultural microcapsule of the present invention has the
following advantages:
(1) Even liquid agricultural active ingredients can be readily
solidified as powder.
(2) It is easy to handle the microcapsules.
(3) The microcapsulea are useful raw materials for solid
agricultural composition.
(4) It is easy to have an active ingredient be stable.
(5) An admixture wherein incompatible agricultural active
ingredients are mixed may be readily obtained.
(6) Such admixture is excellent in storage stability.
(7) Even in the admixture, it is easy to have an active ingredient
be stable.
(8) By a spray-drying method, the microcapsules having almost
uniform particule size can be obtained.
(9) The microcapsules obtained by spray-drying have excellent
fluidity and dispersability.
(10) DL dust can be easily prepared by using the microcapsules
obtained by spray-drying.
(11) The DL dust's adhesiveness to plants is excellent.
(12) Organic solvent is not necessary to prepare solidified
emulsifiable concentrate of the microcapsule. The preparation has
reduced toxicity to humans and environment and alleviates
package-waste problmes.
[EXAMPLES]
The present invention will be illustrated in more detail in the
following examples, reference examples, experimental examples.
Example 1
Mixed DL Dust (Fenitrothion and Ferimzone)
(1) Preparation for microcapsules of fenitrothion
Gum arabic (300 g) was dissolved in water (7,500 g), to which was
added fenitrothion (Sumithion.RTM.: purity, 96.8 %, manufactured by
SUMITOMO CHEMICAL COMPANY LIMITED) (81 g). The mixture was
emulsified using a microfluidizer (13,000 psi, 1 pass) to give an
emulsion. The viscosity of the emulsion was 110 cp(25.degree. C.)
and an average diameter of emulsified particule was 0.8 .mu.m.
Water was evaporated to driness from this emulsion using a spray
drier (inlet temperature: 220.degree. C., rotation speed of
atomizer: 30,000 rpm) to give fenitrothion microcapsules having a
diameter of 5 to 30 .mu.m (fenitrothion content; 20%).
(2) Preparation for mixed DL dust of fenitrothion and ferimzone
The thus obtained fenitrothion microcapsules (15 parts by weight),
ferimzone (2 parts by weight), white carbon (2 parts by weight),
liquid paraffin (1 part by weight), clay (80 parts by weight) were
weighed and mixed by a chaser mill, and further remixed by a flush
mixer to obtain DL dust. The diameter of the DL dust was in the
range of 10 to 45 .mu.m.
Example 2
Mixed DL Dust (Fenitrothion and Ferimzone)
(1) Preparation for microcapsules of fenitrothion
One hundred grams of cyclodextrine containing mainly
.alpha.-cyclodextrin (manufactured by TOYO JOZO Co. Ltd.:
Toyodeline P.RTM.containing 50% of cyclodextrins, specially 30% of
.alpha.-cyclodextrin) was dissolved in water (500 g), to which was
added fenitrothion (purity, 96.8%, manufactured by SUMITOMO
CHEMICAL COMPANY LIMITED) (46 g). The mixture was emulsified using
a microfluidizer (13,000 psi, 1 pass) to give an emulsion. The
viscosity of the emulsion was 120 cp(25.degree. C.) and an average
diameter of emulsified particule was 1.9 .mu.m.
Water was evaporated to driness from this emulsion using a spray
drier (inlet temperature: 220.degree. C., rotation speed of
atomizer: 30,000 rpm) to give fenitrothion microcapsules having a
diameter of 5 to 30 .mu.m (fenitrothion content: 30%).
An emulsion of fenitrothion for scattering was obtained by diluting
2 g of the obtained fenitrothion microcapsules to 1,000 ml of water
without compulsory stirring.
(2) Preparation for mixed DL dust of fenitrothion and ferimzone
The thus obtained fenitrothion microcapsules (10 parts by weight),
ferimzone (2 parts by weight), white carbon (2 parts by weight),
liquid paraffin (1 part by weight), clay (85 parts by weight) were
weighed and DL dust was obtained in the same manner as described in
Example 1. The diameter of the DL dust was in the range of 10 to 45
.mu.m.
Example 3
Mixed DL Dust (Fenitrothion and Tricyclazole)
Fenitrothion microcapsules obtained in Example 1 (10 parts by
weight), tricyclazole (1 parts by weight), liquid paraffin (1 part
by weight), clay (83 parts by weight) were weighed and DL dust was
obtained in the same manner as described in Example 1 . The
diameter of the DL dust was in the range of 10 to 45 .mu.m.
Example 4
Mixed DL Dust (Fenitrothion and Tricyclazole)
Fenitrothion microcapsules obtained in Example 2 (6.7 parts by
weight), tricyclazole (1 parts by weight), liquid paraffin (1 part
by weight), clay (88 parts by weight) were weighed and DL dust was
obtained in the same manner as described in Example 1 . The
diameter of the DL dust was in the range of 10 to 45 .mu.pm.
Example 5
DL Dust (Nitenpyram)
(1 ) Preparation for microcapsules of nitenpyram
Ninety grams of cyclodextrine containing mainly
.alpha.-cyclodextrin (manufactured by TOYO JOZO Co. Ltd.;
Toyodeline P.RTM. containing 50% of cyclodextrins, specially 30% of
.alpha.-cyclodextrin) was dissolved in water (225 g), to which was
added 10 g of nitenpyram (purity, 100%, manufactured by Takeda
Chemical Industries, Ltd.). Water of the solution was evaporated to
driness from this solution using a spray drier (inlet temperature:
220.degree. C., rotation speed of atomizer; 30,000 rpm) to give
nitenpyram microcapsules having a diameter of 5 to 40 .mu.m
(nitenpyram content; 10%).
(2) Preparation for DL dust of nitenpyram
The thus obtained nitenpyram microcapsules (2.5 parts by weight),
liquid paraffin (10 part by weight), white carbon (0.5 part by
weight), gypsum anhydride (15.8 parts by weight) and clay (81 parts
by weight) were weighed and mixed by a chaser mill, and further
grounded by a vandum mill to obtain a DL dust. The diameter of the
DL dust was in the range of 10 to 45 .mu.m.
Example 6
Mixed DL Dust (Bensultap and BPMC)
(1 ) Preparation for microcapsules of BPMC
Two hundred and seventy grams of cyclodextrine containing mainly
.alpha.-cyclodextrin (manufactured by TOYO JOZO Co. Ltd.;
Toyodeline P.RTM. containing 50% of cyclodextrins, specially 30% of
.alpha.-cyclodextrin) was dissolved in water (1,000 g), to which
was added 30 g of BPMC (purity, 99%). The mixture was emulsified
using a microfluidizer (13,000 psi, 1 pass) to give an emulsion.
The viscosity of the emulsion was 95 cp(25.degree. C.) and an
average diameter of emulsified particule was 1.1 .mu.m.
Water was evaporated to driness from this emulsion using a spray
drier (inlet temperature; 220.degree. C., rotation speed of
atomizer; 30,000 rpm) to give BPMC microcapsules having a diameter
of 10 to 50 .mu.m (BPMC content: 10%).
(2) Preparation for mixed DL dust of bensultap and BPMC
The thus obtained BPMC microcapsules (30 parts by weight),
bensultap (2 parts by weight), zinc oxide (5 parts by weight),
white carbon (5 parts by weight), isopropyl phosphate (0.6 part by
weight), liquid paraffin (0.5 part by weight), clay (56.9 parts by
weight) were weighed and mixed by a chaser mill, and further
grounded by a vandum mill to obtain a DL dust. The diameter of the
DL dust was in the range of 10 to 45 .mu.m.
Example 7
Mixed DL Dust (Fenitrothion, Fthalide, Cartap and Ethofenprox)
(1) Preparation for microcapsules of ferimzone
Gum arabic (300 g) was dissolved in water (466 g), to which was
added 100 g of ferimzone (purity 98.7%, manufactured by Takeda
Chemical Industries Ltd.). The mixture was suspended and grounded
by using die mill (flow rate: 15 m/sec, 1 pass) to give a
suspension. The viscosity of the suspension was 128 cp(25.degree.
C.) and an average diameter of suspended particule was 2.2
.mu.m.
Water was evaporated to driness from this suspension using a spray
drier (inlet temperature: 220.degree. C., rotation speed of
atomizer; 30,000 rpm) to give ferimzone microcapsules having a
diameter of 5 to 50 .mu.m (ferimzone content; 50%).
(2) Preparation for mixed DL dust of fenitrothion, fthalide, cartap
and ethofenprox
The thus obtained ferimzone microcapsules (4 parts by weight),
fthalide (1.5 parts by weight), cartap.hydrochloride (2 parts by
weight), ethofenprox (0.5 part by weight), liquid paraffin (1.0
part by weight), antioxidant of phenol compound (Irganox-1010.RTM.,
0.05 part by weight), 1-phenyl-1 -xylylethane (SAS-296.RTM.,
manufactured by Misseki Co., 0.4 part by weight), white carbon
(1.25 parts by weight), isopropyl phosphate (0.25 part by weight),
clay (89 parts by weight) were weighed and mixed by a chaser mill,
and grounded by vandum mill to obtain DL dust. The diameter of the
DL dust was in the range of 10 to 45 .mu.m.
Example 8
Microcapsules of Ethofenprox
Two hundred and seventy grams of cyclodextrine containing mainly
.alpha.-cyclodextrin (manufactured by TOYO JOZO Co. Ltd.;
Toyodeline P.RTM. containing 50% of cyclodextrins, specially 30% of
.alpha.-cyclodextrin) was dissolved in water (1,000 g), to which
was added 30 g of ethofenprox (purity, 97%). The mixture was
emulsified using a microfluidizer (13,000 psi, 1 pass) to give an
emulsion. The viscosity of the emulsion was 68 cp(25.degree. C.)
and an average diameter of emulsified particule was 0.7 .mu.m. The
procedures were then carried out as in Example 2 to give
ethofenprox microcapsules having a diameter of 5 to 50 .mu.m
(ethofenprox content; 10%).
Example 9
Microcapsules of Fenitrothion
Fifty grams of arabic gum and 50 g of polyvinyl alcohole
(saponifized degree: 88 mol %, average degree of polimerization:
400) were dissolved in 1,150 g of water, to which was added 150 g
of fenitrothion (Sumithion.RTM., purity, 96.8%, manufactured by
SUMITOMO CHEMICAL CO.). The mixture was emulsified using a
microfluidizer (13,000 psi, 1 pass) to give an emulsion. The
viscosity of the emulsion was 185 cp(25.degree. C.) and an average
diameter of emulsified particule was 0.9 .mu.m. The procedures were
then carried out as in Example 1 to give fenitrothion microcapsules
having a diameter of 10 to 50 .mu.m (fenitrothion content;
60%).
Example 10
Microcapsules of Fenitrothion
One hundred and forty grams of dextrin (Pinedex#3.RTM.,
manufactured by Matsutani Chemical Industries Ltd.) was dissolved
in 327 g of water, to which was added 60 g of fenitrothion
(Sumithion.RTM., purity, 96.8%, manufactured by SUMITOMO CHEMICAL
CO.). The mixture was emulsified using a microfluidizer (13,000
psi, 1 pass) to give an emulsion. The viscosity of the emulsion was
136 cp(25.degree. C.) and an average diameter of emulsified
particule was 1.8 .mu.m. The following procedures were carried out
by the same as Example 1 to give fenitrothion microcapsules having
a diameter of 5 to 50 .mu.m (fenitrothion content: 30%).
Example 11
Microcapsules of Fenitrothion
One hundred and eighty grams of dextrin (Oilque.RTM., manufactured
by Nichiden Chemical Co.) and 20 g of polyvinylalcohole
(saponifized degree: 88 mol %, average degree of polimerization:
400) were dissolved in 900 g of water, to which was added 86 g of
fenitrothion (Sumithion.RTM., purity, 96.8%, manufactured by
SUMITOMO CHEMICAL CO.). The mixture was emulsified using a
microfluidizer (13,000 psi, 1 pass) to give an emulsion. The
viscosity of the emulsion was 86 cp(25.degree. C.) and an average
diameter of emulsified particule was 0.75 .mu.m. The procedures
were then carried out as in Example 1 to give fenitrothion
microcapsules having a diameter of 5 to 40 .mu.m (fenitrothion
content: 30%).
Example 12
Microcapsules of Pyraclofos (Solidified Emulsifiable
Concentrate)
Fifty grams of arabic gum was dissolved in 200 g of water, to which
was added 35 g of pyraclofos (purity 93%, manufactured by Takeda
Chemical Industries, Ltd.), 13.5 g of sorbitan alkylate
(NKD935.RTM.: HLB 4.3) and 1.5 g of nonionic surfactant of
characteristic polymer (NKD3020.RTM.: HLB 19.0). The mixture was
emulsified using a microfluidizer (13,000 psi, 1 pass) to give an
emulsion. The viscosity of the emulsion was 70 cp(25.degree. C.)
and an average diameter of emulsified particule was 1.3 .mu.m. The
following procedures were carried out by the same as Example 1 to
give pyraclofos microcapsules having a diameter of 5 to 50 .mu.m
(pyraclofos content: 35%). The obtained microcapsules were applied
as a solidified emulsifiable concentrate.
Example 13
Mixed DL Dust (Fenitrothion, Ferimzone, Fthalide and
Ethofenprox)
(1) Preparation for microcapsules of fenitrothion
Gum arabic (140 g) was dissolved in water (560 g), to which was
added fenitrothion (Sumithion.RTM.; purity, 96.8%, manufactured by
SUMITOMO CHEMICAL COMPANY LIMITED) (60 g). The mixture was
emulsified using a microfluidizer (13,000 psi, 1 pass) to give an
emulsion. The viscosity of the emulsion was 124 cp(25.degree. C.)
and an average diameter of emulsified particule was 1.3 .mu.m.
Water was evaporated to driness from this emulsion using a spray
drier (inlet temperature: 220.degree. C., rotation speed of
atomizer: 30,000 rpm) to give fenitrothion microcapsules having a
diameter of 5 to 50 .mu.m (fenitrothion content: 30%).
(2) Preparation for mixed DL dust of fenitrothion, ferimzone,
fthalide and ethofenprox
The thus obtained ferimzone microcapsules (10 parts by weight),
ferimzone (2 parts by weight), fthalide (1.5 parts by weight),
ethofenprox (0.5 part by weight), white carbon (2 parts by weight),
pentaerythritol-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)]propionate
(0.05 part by weight), 1-phenyl-1 -xylylethane (SAS-296.RTM.,
manufactured by Nisseki Go., 0.45 part by weight), clay (82.5 parts
by weight) were weighed and mixed by a nauta mixer, and further
remixed by frush mixer to obtain DL dust. The diameter of the DL
dust was in the range of 5 to 50 .mu.m.
Reference Example 1
Mixed DL Dust(Ferimzone and Fenitrothion)
Ferimzone (2 parts by weight), fenitrothion (3 parts by weight),
white carbon (2 parts by weight), liquid paraffin (1 part by
weight) and clay (92 parts by weight) were weighed and mixed in a
chaser mill. The resultant was further remixed by a flush mixer to
give a DL dust having a diameter of 5 to 50 .mu.m.
Reference Example 2
Mixed DL Dust(Fenitrothion and Tricyclazole)
Tricyclazole (1 part by weight), fenitrothion (2 parts by weight),
liquid paraffin (1 part by weight) and clay (96 parts by weight)
were weighed and DL dust having a diameter of 5 to 50 .mu.m was
obtained in the same manner as described in Reference Example
1.
Reference Example 3
Mixed DL Dust(Ferimzone and Fenitrothion)
Fenitrothion (3 parts by weight), gum arabic (20 parts by weight)
were weighed and mixed by a chaser mill, Ferimzone (2 parts by
weight), white carbon (3 parts by weight), liquid paraffin (1 part
by weight) and clay (71 parts by weight) were weighed and added to
the powder mixture, then mixed by a chaser mill. The resultant was
further remixed by a flush mixer to give a DL dust having a
diameter of 5 to 50 .mu.m.
Reference Example 4
DL Dust (Nitnpyram)
Nitenpyram (0.25 part by weight), liquid paraffin (1.0 part by
weight), white carbon (0.5 part by weight) and clay (98.25 parts by
weight) were weighed and mixed in a chaser mill. The resultant was
further remixed by a flush mixer to give a DL dust having a
diameter of 5 to 50 .mu.m.
Reference Example 5
Mixed DL Dust (BPMC-Bensultap)
BPMC (3 parts by weight), bensultap (2 parts by weight), zinc oxide
(5 parts by weight), isopropyl phosphate (0.6 part by weight),
liquid paraffin (0.5 part by weight) and clay (83.9 parts by
weight) were weighed and mixed in a chaser mill. The resultant was
further remixed by a flush mixer to give a DL dust having a
diameter of 5 to 50 .mu.m.
Reference Example 6
Mixed DL Dust (Fenitrothion, Fthalide, Cartap and Ethofenprox)
Ferimzone (2 parts by weight), fthalide (1.5 parts by weight),
cartap.hydrochloride (2 parts by weight), ethofenprox (0.5 part by
weight), liquid paraffin (1.0 part by weight), antioxidant of
phenol compound (Irganox1010.RTM., 0.05 part by weight), 1
-phenyl-1-xylylethane (SAS-296.RTM., manufactured by Nisseki Co.,
0.45 part by weight), white carbon (1.25 parts by weight),
isopropyl phosphate (0.25 part by weight), clay (91 parts by
weight) were weighed and mixed by a chaser mill, and grounded by
vandum mill to obtain DL dust having a diameter of 5 to 50
.mu.m.
Reference Example 7
DL dust (Fenitrothion)
Fenitrothion (3 parts by weight), isopropyl phosphate (0.5 part by
weight), liquid paraffin (1.0 part by weight), white carbon (3
parts by weight) and clay (92.5 parts by weight) were weighed and
mixed in a chaser mill. The resultant was further remixed by a
flush mixer to give a DL dust having a diameter of 5 to 50
.mu.m.
Experimental Example 1
Stability of Active Ingredients
Each of 20 g of the samples (DL dusts) obtained in Examples 1 to 7
and Reference Examples 1 to 6 were respectively placed and sealed
in sample bottles, then stored at 40.degree. C. for a month.
Subsequently, the samples were immediately removed and content of
the active ingredient was measured using HPLC. The results of the
experiment are shown in Table 1. Decomposition rate (%) was
obtained using the following formula: ##EQU1##
TABLE 1 ______________________________________ Decomposition Ratio
after storage at 40.degree. C. for one month (%) Sample A B C D E F
______________________________________ Ex. 1 5.2 4.8 Ref. Ex. 1
94.5 56.1 Ex. 2 14.7 3.2 Ref. Ex. 3 91.8 60.5 Ex. 3 2.3 0.7 Ex. 4
8.5 4.6 Ref. Ex. 2 90.4 88.6 Ex. 5 1.6 Ref. Ex. 4 10.8 Ex. 6 9.1
Ref. Ex. 5 30.1 Ex. 7 1.5 1.8 Ref. Ex. 6 6.0 16.8
______________________________________ Note) A: Fenitrothion, B:
Ferimzone, C: tricyclazole, D: Nitenpyram, E: Bensultap, F
Cartap
Experimental Example 2
Effects of Agricultural Preparations
Insecticidal effects to Brown rice planthopper (Nilaparvata lugens,
third-larvae) and Green rice leafhopper (Nephotettix cincticep.
third-larvae) for DL dusts obtained in Examples 3 & 4 and
Reference Example 7 were investigated by using 2-leaf-stage rice
seedlings.
Predetermined amounts (10, 30 and 90 mg/stump as an amount of the
active ingredient) of each of the samples were scattered to leaves
of rice seedling at 2-leaf stage, and then, the seedling were
transferred to test tubes. Ten Brown rice planthoppers were
released in the tube at the same day of sample-scattering
(28.+-.1.degree. C.). Ten Green rice leafhoppers were released in
the tube one day after the scatterng (28.+-.1.degree. C.). The
number of survived insects was calculated one day or two days after
the releases. The results of the experiment was shown in Table 2.
Mortality (%) was obtained using the following formula:
##EQU2##
TABLE 2 ______________________________________ Brown rice
planthopper Green rice leafhopper Sample Dose 1 day after 2 days
after 1 day after 2 days after
______________________________________ Ex. 3 10 0 3 13 20 30 0 10
37 47 90 70 87 77 80 Ex. 4 10 0 0 17 27 30 20 27 40 53 90 70 80 70
83 Ref. Ex. 7 10 0 0 10 23 30 0 0 20 43 90 47 63 60 70 Control -- 0
0 0 0 ______________________________________ Note) Figures in the
table show average mortality (%). Control: No agent is scattered to
rice seedlings.
* * * * *